


Oneshots and Tentacles

by Alithea_Korogane



Category: Assassination Classroom
Genre: Alternate Universe - Canon Divergence, Alternate Universe - Soulmates, Alternate Universe - Time Travel, Alternative Universe - Kingdom, Cross-Posted on FanFiction.Net, Crossover, Crossovers & Fandom Fusions, F/M, Gen, Human Korosensei (Assassination Classroom), I Will Go Down With This Ship, Major Original Character(s), One Shot, One Shot Collection, Original Character(s), Originally Posted on FanFiction.Net, Platonic Relationships, Poetry, Prompt Fic, Randomness, Reader-Insert, Short One Shot, Time Travel, Tumblr Prompt, Weird Plot Shit, Why Did I Write This?
Language: English
Status: In-Progress
Published: 2020-07-30
Updated: 2021-01-22
Packaged: 2021-03-05 20:00:14
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 23
Words: 15,360
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/25600963
Author URL: https://archiveofourown.org/users/Alithea_Korogane/pseuds/Alithea_Korogane
Summary: "Same lovable characters,Different timelines and universes,Different ways to tell their stories."-----------This oneshot series is a collection of oneshots of different AUs and canon based stories, whether based on prompts found on internet or original concept.Originally posted in Facebook, but crossposted on Fanfiction.Net.
Relationships: Akabane Karma & Shiota Nagisa, Class 3-E & Class 3-E Teachers (Assassination Classroom), Class 3-E & Korosensei (Assassination Classroom), Irina Jelavić/Karasuma Tadaomi, Kayano Kaede/Shiota Nagisa, Korosensei/Yukimura Aguri
Comments: 5
Kudos: 36





	1. A Soulmate's Song (KoroGuri - Soulmate AU)

**Author's Note:**

> Welcome to Oneshots and Tentacles, an Assassination Classroom oneshot series!
> 
> This is a collection of oneshots I have written for AC, whether based on prompts I found on the internet, or original concept of mine! I love to imagine some situations with the characters so this one was born!
> 
> This was made on Fanfiction.Net a year ago, but because I am now a new member in this site, I decided to transfer this one here too!
> 
> I have to warn you, this is majorly a KoroGuri (Koro-sensei x Aguri Yukimura) centric series, but some ships are welcome!
> 
> I hope you will enjoy this oneshot series of mine!

**Summary for the Chapter:**

> Aguri Yukimura was alone in her home when she heard something, or someone entering in her home.

In a world where soulmates actually exists, where a person and his/her soulmate have a special song only known to themselves, Aguri Yukimura never thought that the one she had never expected to come into her home is her soulmate.

It all started like this...

* * *

Aguri was alone in her humble home when she had heard a loud crashing noise coming from the kitchen area.

She woke up suddenly to the loud noise, fear starting to creep in her soul. She had suspected that her sister was the one who did it, but she had realized that her sister, Akari, is on her filming set at this late hour, so she was sure she was totally alone.

That means it is a total stranger.

Right, a total stranger.

That means there is a thief on her house.

Great.

As she started to stand from her bed and grab the nearest weapon she had, a large bo staff her sister has been giving her for protection, she slowly walked towards the door.

She knew she will be going to die.

As slowly reaching for the door knob, she had heard a male voice singing a tune from the other side of the door, making her speechless and in shock. The intruder was singing...

...her song.

The song that was ringing in her head for years!

"That is impossible!" She thought to herself.

But she knew that it was her song ...which she and her soulmate only knew.

**Notes for the Chapter:**

> Prompt: When people are born, they are assigned a soulmate. They have an original song in their head that only them and their soulmate know. A person just broke into your house and you're pretty sure they're here to murder you. They're humming your song under their breath.


	2. Interdimensional Mistake (Reader Insert)

**Summary for the Chapter:**

> The reader was granted the ability to travel to any fictional world they like, unfortunately, they never expect what is waiting for them on their dream world!
> 
> Why is Koro-sensei and the Class E was glaring at them?

**Notes for the Chapter:**

> There is a slight difference between the Fanfiction.Net version and this one. Since Fanfiction site does not allow reader insert stories, I have inserted my AC OC, Alithea Korogane, in the FF.Net version. It was changed in AO3 version to fit with my original plan of writing reader inserts, since AO3 allows reader insert stories.

I am so happy that my dreams has finally come true.

On my 16th birthday, on unknown circumstances, I was given a special power to travel through any fictional world I want, and being an anime lover, I know what universe I wanted to go and explore.

I closed my eyes as I summoned the power within me, as I could feel myself moving and shifting to a different world.

As I expected, it was my favorite universe: Assassination Classroom.

I thought it will work smoothly and perfectly as it is. My powers, I mean.

But what I had never expect is I landed on the grassy ground in the middle of the night, with a orange barrier covering around the place...and the characters that I had been idolized for years has been looking at me with fear and disgust.

Then they had called my attention, but in one name I never wanted to hear my favorite protagonists calling myself.

"Shiro-san..." The Class E students whispered in a range of emotions...from fear to contempt.

"It is you...[Y/N], the one who made me who I am now...the one who had ruined her life..." Koro-sensei spoke, voice dripping with disgust and contempt. I never wanted to hear that chilling voice of his, directly at me!

And here I was, shocked to hear that revelation, that I was really the Shiro person that was terrorizing the Class E and Koro-sensei, not that Yanagisawa bastard.

What the heck had happened here?!

WHY AM I BECAME A VILLAIN IN A MANGA I HAVE OBSESSED WITH?!

**Notes for the Chapter:**

> Prompt: After gaining the power to travel to any fiction world, you decide to travel to your favorite novel, only to find out that you were the interdimensional evil they've been foreshadowing for the past three books.


	3. Amnesiac Octopus (Amnesia AU)

**Summary for the Chapter:**

> A huge yellow octopus woke up with no memories, while being stuck in a unfamiliar place.

**Notes for the Chapter:**

> WARNING: There is one swear word slipped in this story, so to those little readers, read at your own risk!
> 
> And remember, Koro-sensei never uttered a cursed word! Well, onscreen.

"Who am I?"

I woke up remembering...nothing.

Not even a slip of memory, nothing. Just a empty void in my mind.

But even for a person who had no memory of who I am, I am really sure I WASN'T supposed to be here.

Well, I was on a strange white room, which those people in white coats, who called themselves as 'scientists', looking at me with amazement and wonder, like I am a guinea pig, a lab rat that they wanted to experiment with.

Have you ever wondered why they were watching me with amazed eyes?

And why am I here?

Yes, I was a huge yellow octopus.

Who I found out can move very fast.

Who talks like a human.

Who thinks like a human.

And damn, who smiles like a creepy pervert in the night.

I held my round head and rubbed it, looking at the floor. I wonder why I had never remembered everything about me, for my mind was blank like a clean sheet paper.

What happened to me before all of this happen?!

"Who am I, and why am I a f*cking octopus?!"

**Notes for the Chapter:**

> Prompt:You have recently woken up in the hospital with amnesia. The problem is you are a shape shifter, and can no longer remember your true form.
> 
> Because of the prompt, this is also classified as a Shapeshifting AU. Okay, this is hilarious and weird at the same time.
> 
> In this drabble, Koro-sensei has no memory of who he is! I wonder how he had lost his memory, I will leave it to your imagination.


	4. Son of the Moon (AC OC - Moon God AU)

**Summary for the Chapter:**

> All his life, Yukimura Tsukiro was being followed by a young man who seemed to be look like him. Sometimes, the moon seems did follow him too.
> 
> Now he finds courage to confront the man, who is more than meets the eye.

**Notes for the Chapter:**

> Welcome to the fourth chapter of Oneshots and Tentacles! So here is an AC OC story of mine, and as you can see, this is an alternative universe.
> 
> Tsukiro Yukimura, the AC OC I have featured here, is my OC from one of my fanfic named "The Slithery Child of the Crescent Moon", which is a next generation fanfic. In this story, Koro-sensei and Aguri had a child, made using Yanagisawa/Shiro's spin-off research on antimatter, and that child is Tsukiro (name meaning "son of the moon").
> 
> The story is now on AO3, Wattpad and Fanfiction.Net, under the title, The Slithery Child of the Crescent Moon! You gotta check it out!

When Yukimura Tsukiro was still a young child, he couldn't help notice that the moon is following him all around.

Whether in the car, in the park, everywhere he goes, he saw the same moon following him, day or night.

When he asked his aunt, Shiota Akari, about the issue, she just coughed, suddenly glared at the moon, then smiled forcedly and shrugged, like the good actress she were. "It's nothing, the moon is so big, it is just an illusion that it had followed you," she said, holding the groceries in her arms.

Tsukiro just looked at her in confusion. Being a curious seven year old as he was, he was always wondering about the moon following him. Sometimes, when he had never saw the moon, he saw a glowing young man following him from far away instead, and it seemed to be stalking him.

No one told him why that man or the moon following him, not even his own aunt.

* * *

When he grew older, Tsukiro had finally thought it was just a product of his wild imagination, that it is an illusion that the moon is following him, he is now a rational and logical person. His half twin sister, Yanagisawa Akiko, always convinced him that the moon was not at fault, because the moon was so big, it creates an illusion that it followed him.

Until...One fateful night.

* * *

Tsukiro had saw the young man following once again, the moon once again gone from sight. This time, Tsukiro started to approach the man and tell him to leave him alone.

Imagine the shock in Tsukiro's face when he saw the man in front of him.

The young man probably in his late 20's, wearing an academic dress, with a crescent moon in his large necktie. He has a smile so gentle, he can make people at ease around him.

What's strange is he looks like Tsukiro but older, and has total raven eyes, compared to Tsukiro's raven tinged with orange hues. Compared to Tsukiro, the man wore no glasses. The weirdest thing is...

...And he is glowing and floating, seriously, the man's feet never hit the ground.

And even though the young man keeps following Tsukiro for years, ever since Tsukiro was still a child, the man never aged at bit. Tsukiro rubbed his eyes to see if this is all a dream, but it is not.

The strange man was still there, the moonlight illuminated the young man's figure.

"Who are you?!" Tsukiro had screamed when he had enough, his voice had cracked, "Why do you always follow me all my life?! And why have you never aged?!"

The young man just laughed and spoke gently to Tsukiro, the crescent moon tie was glowing brightly in his chest, "Nurufufufu~ I forgot to do the introductions. My name is Koro-sensei, god of the Moon," and he pointed at the shocked teen with a smile on his serene face, " and you, Yukimura Tsukiro, the son of Yukimura Aguri, who had sacrificed her mortal life to the moon 17 years ago because of her love...

_...is my son."_

**Notes for the Chapter:**

> Prompt: During your childhood, you believed that the moon was following you while you were sitting in the backseat of the car. As you grew older, you passed it off as a product of your wild imagination. Unbeknownst to you, the moon has been actually been following you your entire life. You are the child of the moon.


	5. Summoning A Demon

**Summary for the Chapter:**

> Nagisa, Karma and Kaede decides to do demon summoning out of boredom.
> 
> Imagine the look on the trio's faces when they saw the demon they were summoning.

_"I summon to the darkness of the night, call us a demon of fright..."_

* * *

Nagisa had a feeling that this will totally go wrong.

The RGB trio had a sleepover on Karma's house, and they wanted to do some fun before they will fall asleep. Nagisa wanted to play some boardgames, but Karma never wanted to go with it because it was too boring. Because of that, Karma had convinced the two to do demon summoning, due to his curiosity on Hazama's book of spells that he had borrowed a while ago.

Using Hazama's book of spells, the trio had made a perfect summoning circle and lit candles around it. The lights in the room was switched off, leaving the glow of the candles illuminating the entire room.

Then they had started the summoning.

* * *

_"Release the demon of the night,_

_To answer the questions right._

_This dark spell will open the portal of the other side,_

_And unleash the beast that would never hide!"_

* * *

But they never thought what will happen next will shock them to death.

The summoning circle glowed brightly, as a cold wind blew around the room, blowing the candles off.

Kaede had shrieked in surprise, while Karma was very excited to see the demon.

"Is it working?"

"Dunno, let's find out."

Nagisa lit the candles on, as Kaede and Karma looked at Nagisa. The light covered the room's darkness as the candles lit the room again with its orange light.

What they don't expect is this one...

"Who had summoned me here?!" Shiota Hiromi's shrill voice filled the entire room as she stood ON the summoning circle with an annoyed look in the face, before turning her head around the surprised trio.

Nagisa had swore that he wanted to faint at that hour.

**Notes for the Chapter:**

> You and your friends decide to try and summon a demon at your sleepover. You are completely stunned when your mother appears in the middle of the room when the ritual has finished.
> 
> I am so sorry, Hiromi! I made you a demon here, well, it is for a prompt, and who would be better to place here than the demonic mother of Nagisa Shiota? *lol*


	6. A Demon's Guardian Angel (KoroGuri- Demons and Angels AU)

**Summary for the Chapter:**

> A long time ago, God has passed this one rule: a demon was assigned a guardian angel to guide them to redemption. He had hoped that they will come back to being good as they were before the war between good and evil came.
> 
> Aguri never thought she will be assigned to the most evil demon of Hell.

A long time ago, God has passed this one rule: a demon was assigned a guardian angel to guide them to redemption. He had hoped that they will come back to being good as they were before the war between good and evil came.

Yukimura Aguri was assigned to a demon by the name of Koro.

She was sent to him by the heavens to guide him to redemption, and being a stubborn angel as she was known on Heaven, she will never give up on this, even though she was already informed by her superiors that Koro has a reputation of being the most evil demon of Hell.

But as she said, she will never give up on this, because she believed that there are something good in anyone, and even the most evil demon, which is apparently Koro, has.

When she first saw, she could bear to adore her assigned demon.

She had found Koro cute. He has short and messy dark hair that reaches his nape, and he has beautiful raven eyes, like the night sky. He has a smile that is very charming, and he has a very calming aura around him.

If not because of his demon wings in his back and two horns in his head, he would be mistaken as an angel.

Aguri smiled brightly as she reached her hand to the deadpanned demon, "This is going to be a wonderful friendship between us two!"

**Notes for the Chapter:**

> Prompt: Every demon is assigned a guardian angel in hopes that they'll grow kind enough to go to heaven. You're an angel and you're assigned to a demon that's the sweetest thing you've ever seen.


	7. Karma and Probability (Special Abilities AU)

**Summary for the Chapter:**

> In the world full of people born with special abilities, Karma has the ability to control the probability of things around him. 
> 
> As a test of his abilities around his extraordinary teacher, Koro-sensei, he decided to change the probability of getting an A on his test while purposely answered the test wrong.

**Notes for the Chapter:**

> For the first time in seven chapters, Karma has finally got the spotlight!
> 
> In this story, Karma has the power of luck, based on the prompt I found, and his bug on Koro-sensei Quest.

_"Probability of success has increased to 90%..."_

* * *

Like anyone else in a world where people were born with extraordinary abilities and powers, Akabane Karma has the power of luck.

Yes, the red devil of Class E can manipulate luck.

One of his abilities is controlling the probability of everything around him. He can make one event successful or fail by just a flick of his hand.

It was a nifty power, especially for a student like Karma.

Unfortunately for him, he rarely use it this year in his school, since his teacher, an octopus-like creature by the name of Koro-sensei, came to his life.

When he had first met Koro-sensei, he had used this ability of his to increase the chances of him assassinating his extraordinary teacher, but his powers seems to malfunction. He tried and tried to flick his hands, but did no effect to his Sensei. Koro-sensei still dodged his classmates' attacks every now and then using his Mach 20 speed.

After that incident, he always thought his powers were slowly malfunctioning and fading every second.

* * *

Karma is a genius in Math, but this time, he had to test something.

Koro-sensei had a pop quiz on Math today, and Karma decided to use his abilities this time to check if his powers still worked or something.

He had looked on his paper and tried to increase the chances that he will get an A on this test, then answered it wrongly.

"Time's up!" Koro-sensei chirped after 5 minutes, as he grabbed his students' papers using his speed.

* * *

Karma couldn't believe his eyes.

He got his results of the pop quiz, and he got an F.

"Impossible! I used my abilities in here! How could this be?" He mused to himself, looking at his paper, until he saw a little note that his Sensei had wrote. He was shocked when he had read it:

_"Don't try your magic with me, Karma-kun. I know you used them, so don't rely on them when I give you some tests! Nurufufufufu~"_ _\- Koro-sensei_

Karma was shocked for the rest of the day.

* * *

It was revealed later on that before Koro-sensei became an octopus and got his speed ability, he had the power of telekinesis and mind powers. And he had the ability to recognize a person's ability and neutralize them to his advantage.

**Notes for the Chapter:**

> Prompt: You can control the probability of things around you. When something will start, who will win, etc. You change the probability of getting an A on your test. When you get it back, you see there's a F, with a note reading," Don't try your magic on me."


	8. Why Are You My Clarity? (KoroGuri - Songfic)

**Summary for the Chapter:**

> "If our love's is tragedy, why are you my remedy?  
> If our love's insanity, why are you my clarity?"
> 
> Koro-sensei is wondering why Aguri was considered his only clarity in his life.

**Notes for the Chapter:**

> This is the first songfic of this oneshot series! The song was Clarity by Zedd featuring Foxes! This one was born after listening the remix which was made into bunch of memes on YouTube.

_**"If our love is tragedy..."** _

I asked to myself, as I looked at the crescent moon above me, my skin turned a little blue from sadness.

The crescent moon was glowing brightly tonight, like her.

* * *

_**"...why are you my remedy?"** _

I had remembered her clearly on my mind, her innocent smile, her bright smile, her weird shirts, and her kind personality.

I remember how she brushed off my convincing talks with a smile on her face, like she isn't afraid of a killer like me.

I remember her weird shirts, she wore them to cheer me up, ecen though sometimes I feel annoyed on the designs of the shirt before.

I remember her advices, how she made tests for her students, how she joked and how she cried when she told me she wanted to touch me even for one time.

I thought at first that I will capture her heart and trust to gain some help to escape from that prison they called a lab.

But instead, she captured mine.

And I was thankful for that.

* * *

_**"If our love's insanity..."** _

I remember her sacrifice.

I was supposed to be hit by that tentacle mine. I was supposed to take that shot because I deserved it after what I have done.

But she got the fatal shot.

She did everything to keep me from being evil, even sacrificing her life...for a worthless man like me who had destroyed and took so many lives.

I remember her peaceful face as she lied down on a ravaged lab floor, debris lying around her. I was holding her delicate body, her blood was covering my tentacled hands. She just smiled as she looked at me, as she said her last words: to keep her kids from the dark, to teach them...to guide them for the rest of my days.

She said that before she took her last breath...tears were in her now lifeless eyes. And I was just sitting there, doing nothing! I should have used my tentacles to heal her! Not to destroy!

It was all my fault!

My fault she had died!

And I could never forgive myself for that.

* * *

Now, I was now in a different form, keeping her promise, her legacy.

I was now a teacher, teaching her precious students. The Class 3-E was now the family I never had. I swear to myself that I will protect and guide them, before I will die this March.

I know I will not see them get their diplomas and graduate, but I am now happy because I had now fulfilled her legacy to them.

I clutched the huge necktie in my neck tightly as tears started to fall from my beady eyes. This was her only gift she had given to me, and this is my only memory of her presence.

* * *

But there is one question that was bothering me the entire time.

I looked again at the crescent moon, crying loudly in the night sky, as I swear I could see her smiling face in front of me.

Why?

**_"...why are you my clarity?"_ **


	9. Imaginary Friend (Slight AU)

**Summary for the Chapter:**

> A poor child has an imaginary friend, who tries to teach him what is right and wrong.

**Notes for the Chapter:**

> Welcome to the ninth story in this oneshot fic!
> 
> Okay, this is kinda hard to write, especially I had to mess with some character's backstory.

In one of the darkest slums in an unknown country, there was a little boy.

He was a poor little kid, with messy raven hair that reaches his nape, dark sunken eyes, and thin frame due to malnutrition. He was shorter that kids his age, and he was very dirty. He was wearing tattered clothes, and no slippers.

He never knew his real name and birthday, for he was already abandoned by his parents when he was still a toddler. He was currently staying in dark alleys with his 'friends', who were street children like him.

He is living in a world where food is scarce, but corruption and poverty run rampant.

Trust and love never existed here, betrayal and survival is.

After all of what he had experienced, he is still happy because he had a friend that he could trust even terms of struggle. What's weird about his friend is it was actually non-human and imaginary.

* * *

"You know, little child, you must know that stealing is not a good idea," his imaginary strange friend had said in the child's native language, his tentacles slithering as he walked with the poor child, who was eating bread he stole from a bakery.

"I am already hungry, Mr. Koro, and besides I needed to collect money so I could buy some food later," the child replied, stomach rumbling as if to agree with him. It seems that the bread wasn't enough for him, so he looked around for possible victims to steal.

His imaginary friend, Mr. Koro, sighed and shook his round head as he looked around the place. It was a terrible world for a child, but Koro can't even help the little kid, even though he is considered 'unkillable' by anyone. He can't interfere, he can't even touch anything. He was like a disembodied spirit still stuck on the living plane. All he had only to do is to guide the poor child in front of him.

"Well, if you say so..."

* * *

The child, now on his preteens, had killed his first victim, because he was tasked by a rich man to kill someone.

He had looked at his hands, and it was dripping blood.

It was the blood from his first victim.

Mr. Koro just looked at him with wistful and sad eyes as he saw the teen wiped the blood from the knife on his hands, "You know, you could stop it now. Killing a person is not worth it."

The teen just laughed maniacally and looked at his friend, "But killing makes me earn more money, Mr. Koro! And besides...the blood, the murder...it was enjoyable!"

Mr. Koro never approved of what the teen had said, "No, it is not. It was worse, and even you can earn money in that kind of business, you will be hunted by the rest of your life? Don't you want that?!" he exclaimed, face starting to turn purple.

"This world is cruel, Mr. Koro, and I would rather be involved in this than to be hungry and poor once again. Besides, if you are killed, you die. It is a logic that I learned in this horrible place I had called home. So just be proud of me! You are just a figment of my imagination!" the teen screamed, trying to swipe the knife on Mr. Koro.

Mr. Koro warned him about the future of the teen's job of being an assassin, and his dark fate, but the stubborn teen wouldn't listen and just screamed for Mr. Koro to get out of his life.

He was busy basking on the luxury of wealth using bloody means.

Mr. Koro just looked at the teen with a regretful stare, before fading away, forever.

* * *

Many years after, Koro-sensei thought of his childhood days. He had remembered his imaginary friend who guided him, but he never appreciated and listened.

After being betrayed by his apprentice did he realized his imaginary friend's warning about his future.

And when he saw himself for the first time after the tentacles grant his wishes to be weak, and Kaede Kayano had given him his current name did he realize this one fact.

"I...was warned by...myself..."

Koro-sensei paled at the thought.

"Mr. Koro...was me all along."

**Notes for the Chapter:**

> Prompt: You are your younger self's imaginary friend.
> 
> Well, I kinda narrate about some of Koro-sensei's childhood in here, using some snippets of canon-based facts. I just made a plot story, using the prompt as a base, then this drabble was born!
> 
> Yes, Mr. Koro was Koro-sensei's spirit, who came from the future to be his younger self's 'guardian angel'. But considering how stubborn the young Sensei was in the story, he have a hard time convincing his younger self.


	10. The Cursed Princess and the Ghost Prince (KoroGuri - Ghost AU)

**Summary for the Chapter:**

> Princess Aguri of Kunugigaoka is doomed to marry the Prince of Gengetsu, Kotarou.
> 
> At least, Prince Koro came to bring a smile on her face, but she knew Koro is not already alive, as she has the ability to see ghosts.
> 
> It seems like it was a blessing to her, instead of a curse.

**Notes for the Chapter:**

> Gengetsu (げんげつ) means "crescent moon" in Japanese, the kingdom was named that way as it was one of Koro-sensei's symbols, besides the octopus.

_"This is Prince Kotarou of the Kingdom of Gengetsu, and he will be your fiancé."_

* * *

Princess Aguri of Kunugigaoka was looking at her window, staring sadly at the view. She sighed, as she was looking at the people outside of their castle, happily preparing for her incoming wedding.

Her parents, the King and Queen of Kunugigaoka, was arranging her marriage to the Prince Kotarou of the kingdom of Gengetsu, to maintain peace among the two kingdoms. She was surprised to hear that shocking news, but her mother, the Queen, was telling her that she need to marry Kotarou, or the Kingdom will be doomed to be in war with other kingdom.

Her wedding to the Prince was now widespread across the kingdom, and everyone is happy, except her. She never loved the man, but as a Princess, she had no choice but to follow her parents for the sake of the kingdom.

* * *

"Are you alright, my Princess?"

Aguri looked up from her windowsill and looked at the source of the voice.

It was a man, possibly in his late 20's, with dark hair that reached his nape, warm raven eyes, and with a smile so kind, anyone can melt in his warm smile. He was wearing fancy black robes, with a little crown in his head, its crescent moon-shaped sapphire shining brightly in the sunlight.

What's weird about him is he was floating, and he was actually transparent, you can see through him.

"Oh, it is you, Prince Koro..." She smiled sweetly, as she looked at the man in question. "What are you doing here? I thought you were travelling with some of your 'friends'..."

Koro just laughed as he floated towards the young princess, as he properly arranged his crown in his head, "Well, Karasuma-san never wanted to be with me, and Irina-chan wanted to kill me, even though I was already dead. Being a ghost was hard, especially in terms of having friends."

Aguri snorted as she looked at her black-haired companion, " What about me? You never treat me as your friend?"

Koro's eyes widened as he was flustered, "Of course! You are my friend! And no one can take that away!"

Aguri stood up and brushed the dirt from her gown. "Yeah, no one can ever take it way from us."

* * *

Not everyone knew about this but the princess has the ability to see ghosts and spiritual entities. Her mom said it was given to her by a witch before she was born, and because of that, it was treated as a curse.

When she was a child, she had seen some bad and good spirits roaming around the kingdom, and she tried her best to help the,m, even though her parents were horrified to find out.

But to her, it was a blessing in disguise, especially when she met him.

* * *

Prince Koro is a young prince from the Kingdom of Gengetsu. He was supposed to be the heir to the throne, but he was killed by a mysterious incident years ago. His only cousin, Prince Kotarou, replaced him unofficially, because Koro is the only child of the king and queen. Unfortunately, Prince Kotarou was an arrogant young prince, which treated his constituents as pawns.

As much as she hated this fact, Princess Aguri liked him, as he was the friend Aguri never had. At first, he was an arrogant, spoiled and a cold prince due to him being an only child, but due to Aguri, he had changed for the better and became a sweet and kinda pervertic spirit. Not as she never mind it, of course.

As months and days passed, Aguri has started to fall in love with him, but was afraid to tell him her feelings for the fear of her feelings not being returned.

If Koro was alive, she could be with him. She could be his future wife, not Kotarou. They could live happily ever after.

But it will never happen.

After all, how can she love a man who she knew had died many years ago?

**Notes for the Chapter:**

> Prompt: A princess is arranged to marry a prince as a sign of peace. Problem is that the princess has been cursed with ability to see ghosts and has fallen in love with the ghost of the true prince as it turns out that the man she is supposed to marry is a fraud.


	11. "I teach, that's my superpower." (Teacher's Day Special)

**Summary for the Chapter:**

> "I love to teach, and that is my greatest superpower!"

**Notes for the Chapter:**

> This is actually created last October 2019 in the celebration of Teacher's Month. The theme is the saying, "I teach, that's my superpower," and I could not stop thinking about Koro-sensei.

My name is Koro-sensei, and I am a teacher.

I was teaching 28 students in a prestigious school of Kunugigaoka Junior High School, and I am their homeroom teacher, along with my colleagues, Irina Jelavic and Tadaomi Karasuma.

If you look at me, you will wonder why an huge mutant octopus like me became a teacher, if I could use my powers to help other people, or destroy the world?

The answer is I want to fulfill a promise to someone I care about.

I only have one year, and I wanted to spend it to teach her kids, her precious students.

* * *

I am the one who destroyed the moon, and I will end the world in a year.

But before teaching my precious students and guide them to the light.

I have lots of powers. I can speed up to Mach 20,

I can regenerate quickly, I can shape shift and I can camouflage to any surroundings.

No weapons can ever hurt me, except one, and I am pretty invincible.

I can be a villain, or I could be a superhero.

I could continue my work as a former assassin, or became an agent to the government.

I can help or destroy the world.

I am pretty powerful, and no one can stop me.

But do you know what power I have loved the most?

It is the power to teach.

Because teaching is my superpower, And I wouldn't replace it for anything. She gave this power to me, and I will cherish to the bottom of my heart.

And I will never let this superpower of mine go, because my students need me in this delicate times. I will protect them with all my heart, and that is all matters to me.

Before I die, I will make sure I will see the smile on their faces as they grow into the adults they wanted to be.

That is the power of teaching: it is a mission, full with love and dedication to the students you had cared about, and you will never stop to do it.

Is your teacher have the same power as mine?


	12. The God, The Teacher and The Moon (Crossover - Oneshot Version)

**Summary for the Chapter:**

> Tsukuyomi-no-mikoto was pissed off as hell when he saw his beautiful round moon became a perfect crescent in front of him, so he rushed on to meet the teacher who claimed to have destroyed the moon.

**Notes for the Chapter:**

> This is the oneshot/draft version of my ongoing Noragami/Assassination Classroom crossover fanfic story, "The God, the Teacher, and the Moon". In fact, the summary was from the full version of the fic! 
> 
> This will be incorporating the famous Tsukuyomi Theory, so if you are not a fan of that theory, do not read!
> 
> I will be crossposting the full multichaptered version here on AO3, but here is the link for the FF.Net: https://m.fanfiction.net/s/13406760/1/The-God-The-Teacher-and-The-Moon

Tsukuyomi-no-Mikoto, known to some friends as Yato, was not amused.

The moon god was looking at the moon with bored eyes, his hand was playing with the water beside him, while his Regalia, Yukine, was sitting beside him, looking at his master with a raised eyebrow.

A few months ago, Yato and his friends found out the truth about his true identity as the reincarnation of the exalted moon god, and he was still shocked as of now. From a minor god with no followers, to one of the greatest gods of the heavens...and Yato could never believe what happened to him.

Now his sister, Amaterasu, officially introduced him as the exalted Tsukuyomi, and reinstated his position in the heavens. And because of that, he had lots of responsibilities now, from supervising the moon and the tides, to granting his followers' wishes. But his adventurous side of him was still bugging him to fly away and be the same Yato that he was, but his Regalia was reminding him about his new job.

Yato was looking at the moon, hoping that something great will happen, for he was bored.

What happened next shocked his very core.

The whole moon exploded, leaving a crescent moon in its place. Tsukuyomi...no Yato... stood from his throne and was looking at it with shock, his very being shivered at the fact that the moon was shattered under his watch. Yukine's eyes widened as he stared at the broken moon.

The reincarnated moon god had one thing that bugs his mind right now...

"Amaterasu-san would kill me for this!"

* * *

"Hello, I was the one who destroyed the moon! Nice to meet you!"

The octopus teacher was happily teaching his students, helping them for their midterm exams, while noticing something out of the blue.

He could see three people behind the students looking at him, the tall electric blue-eyed man was looking daggers at him. Koro-sensei smiled widely as he tried not to change his color, as he knew who the man was.

Tsukuyomi-no-Mikoto, the god of the moon, was looking at him with daggers in his eyes, wanting to drown the octopus teacher with his water powers. Any normal person would fear the wrath of the moon god, but Koro-sensei is not normal. He had a secret that no one even knows. He could see people from the Far Shore, yes, and for him it was a curse.

Koro-sensei just winked at them as he passed through them, whispering these words to the trio: "I could see you, yes, don't fret. We'll talk later, class."


	13. Small World (Songfic)

**Summary for the Chapter:**

> Koro-sensei loves to fly, as he always felt that he was free from the past he wants to forget.

**Notes for the Chapter:**

> This is the second songfic in this series, and it was based on the song "Small World" by Idina Menzel!
> 
> I feel Koro-sensei's pain and happiness in here, and I couldn't help but shed a few tears as I wrote this one!

Koro-sensei loves flying.

Ever since he had gained these powers, _these tentacles,_ after _she_ had died because of his selfishness, all he wanted was freedom.

Freedom from his dark past. Freedom from the memories.

Freedom from the dark prison he called 'himself'.

Koro-sensei just wanted to be free.

When he flies around the world, he could feel the happiness and warmth in his heart as he fly around the world at the speed of Mach 20, where he could feel the cold wind blowing on his round head, the sound of sonic boom in his ears as he breaks the speed of sound, and the thrill of flying overwhelmed him.

And he loved that feeling, he will not replace that feeling for anything in the world.

* * *

_"Goodbye, gravity..._

_Goodbye, enemies..._

_I'm going up to a place where the world is small,_   
_Where I can fly above it all."_

He screamed, as he looked at the sight of Tokyo below him, as the crescent moon's light was shining above him. He had screamed so hard, you could possibly hear his voice if you strained your eyes too hard to mute the sound of city noise.

* * *

Koro-sensei knew he would die soon, he can feel it.

March 13 is approaching, and Koro-sensei knew on that day, he will never see his precious students graduated and having a great future ahead, for he knew one way or another, on that day, he will die alone...or take the world, and his students, along with him.

"Aguri, did I do the right thing?"

* * *

March 12, 11:45 pm. Koro-sensei was lying on the ground, battered and tired from the fight he had with his 'creator' and his first student.

Nagisa was sitting on him, shakily holding the anti-Sensei knife and pointed it on Koro-sensei's chest, where his heart has been. His precious students was sitting around him, holding him down. He could feel the sadness radiating on them, and he couldn't help but shed a few tears out and smile sadly on them.

Koro-sensei could see the crescent moon and the Spear of Heaven shining brightly, prepared to take him in.

He could also see Aguri Yukimura, the girl who captured his cold heart and melted it...his love, his lost Leonore...his Juliet, waiting for him on the other side.

* * *

_"If I don't make it, sing my song._   
_From here I'm weightless._   
_No stars are famous,_   
_And the world is small..._ _"_

* * *

"Sayonara...Koro-sensei."

Koro-sensei could only smile and said these last words:

"Hai, sayonara."

As Nagisa had pushed the knife and stabbed Koro-sensei's heart, Koro-sensei smiled as his physical body started to fade away. He can only barely hear his precious students' cries as he had floated away to the moon.

Nagisa's crying face morphed into Aguri's smiling one, welcoming him with open and loving arms.

And Koro-sensei couldn't help but cry happily.

_"...And the world is small."_


	14. Do I Look Like a Princess? (KaraIri - Future Fic)

**Summary for the Chapter:**

> "I don't want to look like a princess. I want to look like a formerly evil queen who reluctantly redeemed herself to the side of good."
> 
> "You read too much."
> 
> "Yeah, I do."

**Notes for the Chapter:**

> Well, this time, KaraIri/KaraRina took the stage with a fluffy future fic! Of course, I found the perfect prompt for them, and I incorporate my other story, "The Slithery Child of the Crescent Moon", in here! Aimi Karasuma, the OC character who was featured on TSCCM, had appeared here, as we all know in canon, Irina and Tadaomi are married and had a daughter.
> 
> If you want to understand this, please read my Next Gen AU fic of mine(TSCCM) on Fanfiction.Net, coming soon on AO3!

5-year old Karasuma Aimi ran towards her parents' room, expecting her parents to be in there. It was the middle of the night, and she was supposed to be asleep, but her hyperactive attitude got the best of her and went to her parents. Her black hair was tied in pigtails and blue eyes shining with wonder, as she was happily bouncing towards the room.

She was right.

"Mommy!" Aimi ran towards her mother sitting on the king-sized bed, who looked at her daughter with surprise. Her mother's long blonde hair was tied into a messy bun, and she wore her favorite nightgown, a light purple dress with little flowers adorning the collar.

Her father was also in the room, arranging a bunch of paperwork that was sprawled on his desk. He was wearing his pajamas and white t-shirt, his usually spiked up hair was unkept.

"Aimi-chan! You should be asleep right now, you have school tomorrow," Irina scolded her young daughter, who was pouting, baby blue eyes looking at her own.

"I just wanted to ask you a question," the five year old quipped, as Irina was lovingly twirled her daughter's pigtails.

"A question?" Tadaomi asked her daughter, as Irina stared at her daughter in understanding. Well, being a 5 year old kid, she was a curious one, so it was obvious that she will ask a lot of questions. "What is it, darling?" she questioned gently.

"Tsukiro-kun had said to me that I look like a princess," Aimi spoke, faint blush in her rosy cheeks. Irina and Tadaomi looked at one another, then to their daughter. Aimi had been friends with Yukimura Tsukiro, a 7 year old boy who was discovered to be the son of Koro-sensei and Yukimura Aguri due to an experiment. Aimi took a liking to the shy 7 year old boy, as compared to other boys she had met. Aimi had apparently inherited her mother's ability to charm people, especially of the opposite gender.

"That octopus' son told you? Well, for once, he never like that octopus and had said something right. Of course, darling, you look like a princess!" Irina laughed as she gently held her daughter's chin and lift it up slowly, "Where do you get that beautiful looks? Well, from me, of course! God blessed you with that charm!"

Aimi's eyes twinkled in wonder, "Really? So that means that you look like a princess too!" she happily asked her mother, while her father raised an eyebrow.

Then Irina laughed, earning a confused look from her husband and daughter.

"Me, looking like a princess?" Irina snorted, looking at her daughter with a smile, "I don't want to look like a princess, I want to look like a formerly evil queen who reluctantly redeemed herself to side of good."

"You read too much," Tadaomi responded, eyes rolling at what his wife had said, as he sat down next to his wife and daughter.

"Yeah, I do," Irina chuckled, as she stared at her husband's dark eyes, her face nearing his, "Seems like the story was fitting for me, Omi-chan?"

Then Irina kissed Tadaomi on the lips, the latter widened as Irina deepened the kiss.

"Ewww!" their daughter covered her eyes with her hands as the couple stopped and blushed. "Well, we kinda forgot that she is actually here," Irina teased, as she tickled their precious daughter, Aimi's laugh resonating in the room. Tadaomi smiled as he joined at the tickling contest, as Irina laughed.

The Karasuma household was full of joy at that day, and the couple could wish these little moments will be treasured and kept forever.

**Notes for the Chapter:**

> Prompt:  
> "I don't want to look like a princess. I want to look like a formerly evil queen who reluctantly redeemed herself to the side of good."
> 
> "You read too much."
> 
> "Yeah, I do."


	15. Slithery Paradox (Time Travel AU)

**Summary for the Chapter:**

> First Shinigami and Aguri felt intense joy when they first touched, hours before the moons explodes into a permanent crescent. It is a bittersweet moment, as they both think of the future ahead of them.
> 
> But it all changed when a huge yellow talking octopus burst out of a mysterious portal showing out of nowhere, crashing their intimate moment!
> 
> Just who the heck is Koro-sensei, and why he likes to annoy Shinigami?!

March 12, 20xx, 9:15 PM.

It was a normal evening for everyone, but for the First Shinigami and Aguri, it was a momentous moment for them.

Neither they had expected, even people around the world, that this day...will be going to be the weirdest day ever.

* * *

For the first time, he and Yukimura Aguri had finally touched, after a year of comfort and soltitude, with a glass barrier separates them.

Aguri looked at the assassin's eyes as she smiled, feeling the warm touch of the glowing tendrils that came from the assassin's black locks. The Shinigami looked at Aguri with a gentle look on his face as he behold the sight of his beloved.

"I know you can do it, Yukimura-san," he spoke gently, as he touched the glass barrier that separates them and placed his forehead on the glass. Aguri followed, her hand mirroring his own, her own forehead touched the glass as she chuckled.

"I know. Say, you can call me Aguri from now on, for you know, we are now close to each other," she spoke as she looked at Shinigami's eyes once again.

The Shinigami widened his dark eyes as he stared at Aguri's own, a bright smile formed in his lips, "Really?"

Aguri laughed as her voice chirped up, "Sure, why n-"

She was interrupted when a blast of light flashed brightly and a blast of cold wind blew behind Aguri's back, making the two jump up in surprise, the Shinigami's little tendrils started to retract back in his dark hair. He squinted at the bright light, while Aguri had yelped. Papers were strawn everywhere, as the cold wind blew them away.

When the bright light faded, the assassin glared at where the light originated and saw a strange portal.

Suddenly, something big and yellow pops out of the portal, and crashed on the floor, landing besides Aguri, who screamed and jumps towards the opposite direction.

"NYUYA! THAT HURTS!"

The two stared at the speaker in shock. Out came an octopus-like creature, wearing a black and red academic robe with a huge necktie, an orange crescent moon etched on it. He was yellow, his round head bears pinprick eyes and the widest smile the two had ever seen. A graduation cap with an orange tassel was perched in his head. His tentacles were slithering, while he was clutching his head in pain.

The Shinigami and Aguri gaped like fishes out of the water as they try to ponder on the sight in front of them.

"Ugghhhh...That is worse than trapping me in my Ultimate Defense form..." the octopus groaned, as he winced on the pain. He stood up, as his pinprick eyes started to clear out the fog in his sight. He had looked around, still nursing his throbbing round head, and saw the two, who was still gaping.

Suddenly, his pinprick eyes widened as he approached the frightened woman. "Aguri?! How are you here? It is impossible!" He reached and touched Aguri in the shoulders, shaking her gently.

"Stay away from her, you creature, or I will kill you..." the man glared at the octopus, pounding on the glass angrily.

The octopus heard the Shinigami's warning and stopped shaking Aguri, releasing her. Aguri was still frozen in place.

"Sorry," the octopus apologizes as he turned to look at the man, who was still glaring, "And as if you can escape there."

The creature's head changes color, green and yellow stripes appeared, making the Shinigami being infuriated further.

Aguri snapped of her reverie and politely asked the creature, "Um...hi? Who and what are you? How do you know my name?"

The octopus looked at Aguri happily and raised his main tentacle, signalling for Aguri to hold it and shake hands, " By the way, my name is Koro-sensei, yes, I am an octopus and a teacher, and I could say that I am from the future!"

"A teacher?" The Shinigami and Aguri asked the octopus, while the said octopus nodded too fast.

"Glad to meet another teacher,"Aguri smiled nervously as she shook hands with the octopus, which was now dubbed Koro-sensei. She stared at him, and feels something weird.

 _"He is something familiar. Where do I see him?"_ she thought to herself.

The Shinigami was not impressed, "From the future? Tch, as if I could believe that. Time travel is impossible!" he argued.

The octopus laughed as he touched the glass which separates him from the infuriated assassin, "Nurufufufufu~ I could tell you this, in a few months, you will eat those words you have spoken today."

The assassin's hands shook and started to wriggle like tentacles, while his eyes glowed red as he looked at the sniggering octopus in anger, "Why you-"

"Shinigami-san, calm down!" Aguri scolded the assassin, making the assassin stop and folded his arms in annoyance, still glaring at the octopus. She looked at Koro-sensei, who was starting to fidget on his crescent moon tie.

"Well, Koro...sensei...what brings you here? It is not everyday you can meet a...time traveler here, more like an alien," Aguri asked, earning a wince from the octopus.

"What are you, the Doctor from Doctor Who?" The Shinigami commented as he smirked, earning a narrowed glare from Koro-sensei.

"I am not an alien! I was born and raised on Earth, you know! And I have you know, the Doctor is only fictional, not me!" Koro-sensei childishly screamed, as steam started to come out from his 'ears'.

The Shinigami hollered and whistled mockingly, as Aguri groaned. Ever since the Shinigami was experimented by his fiancè, he seems to have a difficulty in hiding his emotions and desires. And that means being a pervert, a petty and proud person rubbed off him.

"Shush," Aguri scolded the hollering assassin, as she started to notice the papers and stuff strawn around the place. Out the corner of her eye, she noticed a roll book not far from where Koro-sensei landed.

While Koro-sensei and the First Shinigami were still glaring at each other, Aguri picked the roll book and read the front cover.

**_Kunugigaoka Junior High School_ **

**_Class 3-E_ **

**_Roll Book_ **

Aguri was confused. She had remembered she left her roll book at the Class E building, as she was the homeroom teacher of the Class E of Kunugigaoka Junior High. She noticed the small details of the book, and see that it was kinda old and worn out. Scratches and small stains lined at some parts of the book cover. Aguri noted that her own roll book was kinda new, for it was still the start of the school year.

_"How come Koro-sensei possessed this?"_

She opened the roll book and read the contents inside, her eyes widened as she scanned the front page.

It was the names of her current students, but with a few unfamiliar names added on it. There were also little octopus doodles around the page.

Aguri would find it cute, but her mind couldn't comprehend the fact that Koro-sensei, whom she had swore she had never met him in her life, has her roll book.

She looked at the two men (?) behind her, and she could swear she wanted to slap their heads at their childish glares shooting at each other. She turned a page again, and this time something fell out.

She picked it up and realized it is a photograph.

Her dark eyes scanned the photograph and gasped quietly.

The photograph has her own current students on it, with few additional faces on it. Koro-sensei was there, there are two adults standing in the background, a purple-haired girl in a student's phone, a silver haired boy with a bandana, and it even had a student who have exactly resembles her younger sister Akari, only with green hair.

What's weird is she is not in the picture.

She needed answers.

She turned around and decided to confront the octopus, who was still glaring at the dark-haired test subject-slash-assassin on the other side of the glass wall.

"What is the meaning of this?!" She spoke harshly, holding the roll book and the photograph tightly, her usually kind eyes narrowed.

Koro-sensei and Shinigami's arguement stopped at Aguri's outburst, the two of them confused on what Aguri was talking about, until Koro-sensei noticed what Aguri was holding. He gasped as sweat started to form in his head.

"Why do you have the roll book? This is my roll book, this is my class! Why do you have this picture? These are my students, why are you here in this picture, along with these people I don't know? Why am I not here?" Aguri yelled, raising the photograph for emphasis.

"Who really are you?!"

Koro-sensei's head bowed down as the Shinigami looked at the photograph in awe.

Aguri's voice was raised in anger as she held the roll book tightly, "Can you explain to me why are you-"

"Because..." Koro-sensei spoke quietly, his pinprick eyes stared at Aguri's dark ones, while the dark-haired assassin looked at the two with confusion.

"Because what?"

Koro-sensei took a deep breath as he let the truth out, "As I said, I am from the future. In my time, they become my students. And I become their homeroom teacher."

The Shinigami and Aguri gasped in surprise at the revelation.

"But I am their homeroom teacher!" Aguri spoke in a raised voice, shaking her head in disbelief.

Koro-sensei stared at Aguri with sadness in his pinprick eyes, while Shinigami narrowed his eyes at the octopus.

"Not anymore."

"What do you mean..Not anymore, octopus?" the Shinigami angrily questioned the octopus, while Aguri had tears in her eyes.

Koro-sensei looked at the Shinigami then at Aguri. His permanent smile was there, yes, but his eyes showed emotions of grief and sadness. He sighed deeply, as his eyes spotted a huge gift box with a black fabric inside it.

His tentacle reached the gift box and grabbed the black fabric with care, earning a surprised look from Aguri and a glare from the Shinigami.

"Hey, Aguri gave it to me! Take it back!" the angry raven-haired man yelled, as Koro-sensei stared at the black fabric.

It is a huge black necktie.

Koro-sensei laughed gently as he held the necktie carefully, lost in the memories, "I remember she gave me something like this at the day we first touched. It was a necktie too, you know. I remember her smile when she gave me this, and I remember how at first I kinda disgusted at her fashion choices. But when her precious light faded away from me, I started to realize its importance. Her memory...this was the one who keeps me grounded. The one who made me remember her after all these months...and the reminder of my promise to her," he spoke sadly, as his tentacles traced the fabric before putting it back in the box, "I always carried her gift always, to remind me of the promise to teach her children. That is why I became a teacher."

Aguri stared at the sad octopus, pondering on his words, as she saw the octopus touching his own necktie with a crescent moon emblem on it with a longing look. Her mind was confused at first at what the octopus was babbling about, until she had focused on what he had said.

_I remember she gave me something like this at the day we first touched. It was a necktie too, you know. I remember her smile when she gave me this, and I remember how at first I kinda disgusted at her fashion choices._

She stared at the crescent moon necktie of the octopus, then at the necktie on the box. She had noticed that besides the crescent moon emblem, the neckties looks exactly the same.

Now to think about it, Koro-sensei's voice was similar to someone she actually knew, just a little happy and high...and she just noticed it.

Her eyes widened as she started to put two and two together, and it seems the assassin did it too.

"What...the...heck," the Shinigami slowly spoke, as his eyes widened at the realization, "It can't be!"

Koro-sensei stopped at what he did and cocked his round head in confusion, "Can't be what?" he questioned in a high-pitched voice, but suddenly his grin grew wide as he also realized what the two was thinking about.

"YOU CAN'T BE ME!" The assassin screamed in horror, as he pointed at the octopus in accusation.

"Yes, you are me," Koro-sensei sniggered, his head changes color as green and yellow stripes appeared, "Nice to meet you, human me!"

"I BECAME YOU?!" The Shinigami screamed again, his eyes still widened in shock, his face scrunched in disgust.

"I am very much afraid, _Shinigami-san_ ," Koro-sensei replied.

The Shinigami looked at the octopus up and down as he still screamed in horror, "I BECAME A HUGE UGLY AND CHILDISH OCTOPUS?!"

Koro-sensei was offended at his past self's words, his head turned red in anger, yelling childishly, "I AM NOT CHILDISH! AND I AM HANDSOME LOOKING!"

* * *

**_Omake:_ **

"I am glad that you became a teacher," Aguri commented, a joyful smile graced her angelic features.

"Oh, I can't believe that I became one too. Your students are sweet and brilliant, and your sister is exceptional," The octopus sat at Aguri's table, as he decided to grade at Aguri's students' testpapers.

Aguri grinned as she was delighted to hear those, "Glad to hear about that, even though I kinda found out that my fate will be sealed this midnight."

"Kinda weird Yanagisawa hasn't come in yet and see the scuffle here," Koro-sensei commented as he played some games on his smartphone.

"Yeah, it was kinda weird," the Shingami's voice was low as he still glared at the octopus, arms folding in a childish manner.

"Nah, few hours from now, something will happen that will sent him running. Well, this will cause a paradox, now that you know about the information," Koro-sensei shrugged.

"I am sure we will still carry on, even though we know what will happen," Aguri spoke, a smile still gracing her features.

"Well, why did you change?!" The Shinigami still glared at the octopus, his face still scrunched in disgust as he found out he will become a real-life alien-looking creature who can speed up to Mach 20.

"To be honest, I still miss this human body of mine. In that body, I am handsome and can be called a pretty boy with great fashion choices, before I go on rampage and destroying this damn place...But I love this form now, I am now a teacher, by the way...but if I still had this handsome face, girls would prefer me than Karasuma-sensei!" Koro-sensei spoke happily.

The two was confused at what the octopus was babbling about.

"Eh? What the heck are talking about? Who's Karasuma?!"

**Notes for the Chapter:**

> This is a kinda long chapter I made, and it tackles about time travel!
> 
> This is kinda based on a 'what if' scenario of what if Koro-sensei was given a chance to go back to the past, and meets Aguri again. This is originally a short incorrect quote I made too, just made it longer.
> 
> And because it is a time travel fic, Doctor Who was referenced here! And sorry I just ended it there, it became too long to continue.


	16. Till the End of Time (S2E22-24 Canon Divergence AU)

**Summary for the Chapter:**

> The story ends with Nagisa delivering the last blow on Koro-sensei, on the arms of his precious students. At least Sensei knew his students will be happy looking forward to the bright future ahead of them.
> 
> What if we change a single detail in the story?
> 
> I could tell you, one little moment can change everything.

**Notes for the Chapter:**

> The students' dialogues are on italics while Koro-sensei's dialogue is on bold-italic.

_"I am so sorry, Koro-sensei, goodbye."_

SLASH!

**_"Isogai-kun!"_ **

_"I am too scared to die!_

SLASH!

**_"Kurahashi-san, Kanzaki-san!"_ **

**_"NO, PLEASE DON'T DO IT!"_ **

SLASH! SLASH!

**_"I BEG YOU, DON'T DO THIS TO THEM!"_ **

* * *

Koro-sensei was devastated, his beady eyes widened in shock as he pondered on the terrible sight infront of him, his tentacles clenching and shaking in shock and anger.

He had failed these kids.

He had failed her.

He had sworn on his life that he will protect them at all costs, as he had failed to protect herfrom dying that night because of his mistake.

But he had failed.

**_"I am so sorry, Aguri. I never fulfilled my promise."_ **

* * *

Now he was all alone, looking at the bloody corpses of his precious students, killed under the tentacles of his wayward apprentice.

The apprentice who betrayed him and put him in this horrible situation.

The apprentice whom he failed to nuture and love, the child who just wanted his love and attention, but because Koro-sensei is stupid enough not to notice the child's growing hatred of him, that child had been strayed from the right path because of him.

He crawled towards the nearest corpse, the body of his dearest troublemaking student, Akabane Karma, who was holding Okuda Manami's lifeless hand. It seems that at the last moment, the redhead chose to protect the meek and innocent girl, as they were both killed by Koro-sensei's apprentice in a blink of an eye. Their chests showed a huge gaping hole, where the monster had stabbed through them, their innocent blood gushed like a rumbling red waterfall. He also saw Nagisa's lifeless corpse not far away, along with some of his classmates' bodies.

All 29 of them, killed.

His colleagues, Irina and Karasuma, first perished while trying to protect their students, their bleeding bodies lying on the cold hard ground. Ritsu was not exempted too, her huge computer was also broken beyond repair during the fight, leaving her unuploaded data erased and disappeared, leaving Koro-sensei alone.

Koro-sensei shakily held Karma's hand, tears started to fall from his beady eyes, his permanent smile never radiated its usual cheerfulness, only sorrow and grief.

He screamed to the night, as he had never forgave himself for making them killed.

He is the Reaper, death always follows him everywhere.

It was a curse he couldn't escape.

**_"It was all my fault."_ **

* * *

His tentacles contorted as his emotions distorted them, the boiling anger inside him is finally unleashed.

The monster he was destined to be was now unleashed, ready to grasp his prey.

Yanagisawa looked at the monster before him, smiling with glee, while Koro-sensei's apprentice was preparing to counterattack his master.

**_"You killed them! Now you two are going to pay for this!"_ **

* * *

Koro-sensei looked and smiled sadly at his first student, as he proceeded to stab him at the heart. He knew it was not the child's fault for becoming who he is now.

Yanagisawa was also flung outside the anti-tentacle barrier, and being injected with tentacle implant leaving the scientist damaged beyond repair.

And Koro-sensei was happy for that. He finally got his revenge.

As his first student had been finally been put to rest, fading away to the dark, Koro-sensei landed on the cold bloody ground. He looked up, and saw the Spear of Heaven glowing brighter every second.

**_"It was time, but they are already gone."_ **

* * *

Koro-sensei wanted his students to deal the final blow on him.

But they were taken away from him before they all do.

They can never follow their dreams anymore, they can never go to high school and college, graduate, work and build families anymore.

Their parents would grieve for the rest of their lives, and Koro-sensei would be blamed for their deaths, sealing his legacy as the monster who had murdered 29 innocent lives in one night.

Koro-sensei don't want to live anymore.

At least, he will be with them on the other side.

With his students.

With his colleagues.

With the his love of his life

Together till the end of time.

With a last look on his students' lifeless corpses, he whispered a lullaby he had cherished in his heart.

**_"Sensei loves you with all his heart,_ **

**_It is time to say goodbye._ **

**_I will hope someday we will meet and reunite,_ **

**_Happily together on the other side."_ **

* * *

The clock strikes twelve, and Koro-sensei's eyes shed its final tear.

And a bright reddish white light shone on him and the whole mountain, as he faded away through the night.

It is a cruel fate that no one did expect.

**Notes for the Chapter:**

> Here is the 16th oneshot I made! This was based on the possibility of a darker twist on Assassination Classroom ending, where Yanagisawa/Shiro and the Second Reaper had killed the students first to make Koro-sensei hopeless and vunerable to die, but it only make Koro-sensei angrier.


	17. Consequences of Killing Him (Immortality AU)

When Nagisa killed his beloved sensei, Koro-sensei, that night, he thought he will only carry the burden of a memory, the dreaded memory of Nagisa delivering the final blow in their beloved teacher who truly cares and loved them with all his heart.

He was utterly wrong.

For he had forgotten one thing, the forbidden rule that actually exists in their world.

* * *

Imagine the look on Nagisa's face when he woke up looking at a bunch of people with sophisticated high tech gear. Nagisa, being a perceptive person, could infer they were archeologists because of the clothes they are wearing.

They found him.

After a thousand years.

Nagisa cursed under his breath, as he looked at the curious archeologists looking at the cave he was trapped in, then to himself.

He never planned to spend a thousand years, still alive and kicking, just because he killed his precious teacher.

Who happens to be a the former legandary assassin called the God of Death, who happens to kill a THOUSAND people before being caught, being experimented, and becoming the greastest teacher Nagisa and his classmates ever had.

* * *

He had remembered what Karma had said to him thousand of years ago.

_"I wanted to be the one who killed Koro-sensei, but that rule. Koro-sensei is still an assassin, a killer, even though he is changed. We can't change the rule, Nagisa. Call me a coward, and I don't want you to suffer, but we leave no choice."_

_"If you kill a serial murderer, because of that rule, you may live longer than any creature here on Earth, possibly forever, unless someone will kill you in special circumstances. You can't kill yourself, you can't be killed in an accident or illness."_

_"Some of his victims may have a longer lifespan, if Koro-sensei never assassinated them. Those lifespans transferred to him, and eventually to you when you killed him."_

_"You wanted to carry his legacy, right? You got it, Nagisa. You carried his burden."_

_"You killed a serial murderer, but you suffer the consequences."_

_"We will die, but you will live forever."_

**Notes for the Chapter:**

> Prompt: When you kill someone, their remaining lifespan is added to yours. Archeologists have just found a cavern, apparently sealed off for thousand of years, with a single person living inside.
> 
> I am back with a new prompt-based fanfic featuring our favorite bluenette!
> 
> When I first red it on Writing Prompts Facebook page, I immediately remember Nagisa, so this idea was born.
> 
> Okay, this is the last of the crossposted chapters from Fanfiction site, that means the next chapters will be new ones!
> 
> I hope you will all be safe and sound in this ongoing pandemic!


	18. Come Little Children [Part One] ('Children of the Night' AU)

**Summary for the Chapter:**

> "Come little children,  
> I'll take thee away,  
> Into a land of enchantment..."
> 
> While a mysterious woman sang the long forgotten lullaby, her form fizzled a little bit as the screen started to glitch, she had opened an old and dusty book, looking at the pictures contained inside wistfully, as she started to narrate.
> 
> "I remember it like it was yesterday..." 

**Notes for the Chapter:**

> Hello, I am back with this sorta new chapter. 
> 
> This story was actually created one year ago, when I hear Erutan's version of the song "Come Little Children" from Hocus Pocus, and the MLP animation video, "Children of the Night". 
> 
> It was supposed to be a multichaptered story, but apparently I only wrote two chapters because I lost interest. Although, I have plans to revamp the story, but it is still undecided as of now.
> 
> The original title of this is "Children of the Crescent Moon", but I changed it because I have an ongoing fanfic story with a kinda similar title.
> 
> I hope you enjoy this little gem.

On an old shack on the top of a hill, in a croom filled with chairs and tables, there was big piece of machinery on the back of that room. It was huge and black, with a dusty screen in it. It looks like it was abandoned for years.

Suddenly, the screen glowed, as it suddenly turned on by someone, which is weird because the shack was actually deserted for years.

Then it glitched for a few seconds, as jumbled numbers were flashing on the screen. After the numbers vanished, the screen became static, before it shows a person in a dark cloak, her face was covered in its huge hood. It was a woman obviously, possibly in her teens, but her voice sounds mature than she looks. She was holding a huge book, a little old, but still as good as new.

Then she smiled, as she opened the old book, looking at the pictures contained inside, as she started to narrate.

* * *

**_"I remember it like it was yesterday..."_ **

* * *

_It was 7 years ago, 70% of the moon was shattered, and no one knows who did it, they thought it was just an passing asteroid destroying it._

_But one day, in a little hill where a little shack some kids called a classroom was standing, a strange octopus-like creature came, and claimed that he is the one who destroyed the moon, and will do the same thing to the Earth in a year._

_He had said that he need to be assassinated in a year, before they graduated, therefore dragging those 28 children into a world of assassination._

_The higher authorities had promised everyone, that the students of the End Class will claim the bounty, if they managed to kill the monster who was teaching them, they will help the kids with the assassination._

_The creature taught them a lot of things, from academics to life lessons, while these kids try to kill him. While at his care, the End Class rose to the top, thanks to him,as they were breaking the norms of the school._

_Eventually, little by little, the students came to love him, but never admitted it, for the fear of breaking their bond._

_One fateful day, one from his 28 beloved kids had shown her true self and take revenge,paving their way to finding out about his true past, being a great assassin and all. He was truly doomed, bound to explode at the day he claimed he will destroy the whole world._

_A civil war was waged, as they were to decide whether to save or kill their teacher. It was a great fight, but at the end, they were united together to save him, even after finding out about the possibility of him not exploding._

_But all this time, they were betrayed by the higher authorities,they were now one step ahead from them._

_He was caged by a shield of Earth, doomed to be dispersed by a spear of Heaven. His students were on their own, to see him, even for one last time._

_They fought their way, and here they are, with smiles on their faces, they celebrated his given birthday. It was very joyous..._

_...Until it was distrupted by his creator and the creature's former student. They came back to kill him, to avenge their lives._

_They fought for revenge and spite, tentacle to tentacle, with a battle of Mach speeds and sonic booms. It was his last stand, his last fight to the end._

_With gratefulness and regret, the student who formerly attack him in revenge helped him fight, for him and for her deceased sister, distracting the enemy so the creature can heal....but in return, her life was taken away by a stab so fatal._

_His creator taunted him, saying mean words to the woman he had cared, the sister of his beloved student._

_Out of regret, sadness and rage, the creature's face changed into a grostique form, his aura emits a menacing one, while his face wrinkles and turns black. His true self, the monster he was trying to hide after all these months, was finally set free._

_His creator laughed crazily, as he saw the tragic sight infront of him, as the teacher unleashed his true self. The creature's beloved first student, now changed into a grostique creature, takes watch, before attacking his former master with his own powers, aided by the creator's help._

_It was very bright, as the teacher and the student fought with all their might, as a huge beam coming from them clashes at last. It was a spectacular sight, if not the situation so tense._

_But the teacher never lets his anger take over him, he had channeled his powers through a myriad of emotions, which turned a rainbow of colors, used to defeat his first student, as their memories flashed between their eyes._

_With a stab in the gut, in a flash of bright light, his first student was defeated, his dying words says his true wish, the recognition he wants from his mentor. The teacher smiled sadly, as his young apprentice disappeared from sight, floating away in specks of light._

_The teacher approached the bloody body of his precious student, with sadness in his beady eyes. He started to remember his student's older sister, who suffered the same fate as her. It was still etched on his mind, that tragic day. With determination, his little tentacles started to do its miracles, trying to heal her. He fixed and revived her, her blood replenished, her wounds gone, it is a miracle for everyone._

_She woke up, grateful for the teacher, even trying to hide her embarrassment over little chest._ (The narrator chuckled.) _They were happy to see her alive and well._

_But their happiness stopped, when the creature finally fell down in exhaustion, satisfied with his doing._

_But his next words shocked his students and his two colleagues._

_"It's time."_

_And 30 people around him knew what it means, and they dreaded it._

_It is time to say goodbye._

* * *

The woman wiped her eyes, but she still kept that hood on.

* * *

_With hesitation, they approached the exhausted teacher, their hands shaking, as their hearts pounding so fast. Some tried to stop their tears from falling._

_They tried to be strong._

_Can they do this?_   
_Will they do this?_   
_Are they ready to let him go, their precious teacher?_   
_These thoughts haunted in their minds._

_They had decided and raised their shaking hands, as their leader asked them. They don't want to kill their sensei, but they had to._

_With shaking hands and broken hearts, they held him down, his weakness. They hold down his tentacles, one by one, while the two grown ups stood beside them, and looked at them with sadness._

_The creature looked at them sadly. If only he was spared, he would be with them for a little longer and see them grow into successful grown-ups they will be._

_An inffeminate boy volunteered to deliver the last blow, the stab to their teacher's heart. No one relented or even argued, they knew he deserves to do that honor, for he was the best assassin in their class._

_The creature entrusted the students to his two dear colleagues. He knew they would take care of his precious students when he was gone._

_With heavy hearts and crying eyes, the last roll call was delivered._

_Their names were called, as they struggled to answer without crying. They can't bear it, the sadness this moment bring._

_They don't want him to go._

_One by one, each student was called, until he had mentioned the last student, and softly spoke about how they were proud of him._

_The inffeminate boy struggled to do the job, his hands shaking. He hesitated to deliver it, as he tearfully looked at his teacher._

_He was tense, his nerves were shaking, and he could swear his emotional wavelength was too high._

_Until he can't take it anymore._

_He screamed loudly, as he harshly raised his hands in preparation to stab him._

_But he was stopped by his teacher's gentle tentacle holding his nape, calming him. He just wants the boy to smile, for him. He couldn't bear to see his student cry, even at his last day. He just couldn't._

_The boy just smiled as he calmly pointed the green knife to the creature's necktie. With tears in his eyes and a smile on his face, he had said his final words for his dearest sensei._

_"Goodbye...Koro-sensei."_

_The creature smiled, as he looked at his student for the last time._

_"Yes, this is goodbye," he spoke softly. He looked at his other students and smiled softly._

_Alas, the boy pushed the knife to the creature's heart, as the creature closed his small eyes, his last dying breath was now gone. The boy looked at his teacher, as specks of yellow light started to appear from the creature's body._

_Twenty-eight students and 2 teachers looked in awe and sadness when the creature's body started to turn into glowing specks of yellow light, floating away to the barrier and to the crescent moon, leaving his ruined clothes and grieving Class E family, as the specks of light disappeared to the dark skies forever._

* * *

The woman in the screen smiled sadly, as her lower part of her face was shown by the light of her room. She was looking at the book with longing, her little fingers swiped at the pictures in the current page gently.

She hummed, and gently closed the old book, before looking outside at the room window, as far as the screen's angle could see.The broken moon, which returns its round shape after 7 years, although a little smaller than before, has magically turned into a crescent moon again. It was like the one from 7 years ago.

For someone who never knew the whole story, they will think this was very weird, but the woman knew.

She looked at the closed book again, and continues to speak.

* * *

_**"Nobody knows we're still here,** _   
_**Smiling beneath the moon while remembering our dear teacher..."** _

* * *

Then the woman removed the hood from her face, revealing a young-looking face, with blueish eyes and light purple-pinkish hair tied into unique pigtails, adorned an electronic-looking headband.

It was the Autonomous Intelligence Fixed Artillery, also known as Ritsu.

Ritsu looked at the moon again, with a smile on her face.

* * *

_**"....for we will be his children of the crescent moon."** _

* * *

Then Ritsu's face fades away before the screen turns into static and turned off, possibly for the final time.

**Notes for the Chapter:**

> As you can see, it was just focusing on retelling the plot of Assassination Classroom on the point of view of someone else. The second chapter of this story is where the creepy thingy started. 
> 
> This was actually made on my old phone's messaging app because it was a crappy phone.


	19. Come Little Children [Part Two] ('Children of the Night' AU)

**Notes for the Chapter:**

> This was the part two of the story posted on Chapter 18.
> 
> This story was actually created one year ago, when I hear Erutan's version of the song "Come Little Children" from Hocus Pocus, and the MLP animation video, "Children of the Night". 
> 
> It was supposed to be a multichaptered story, but apparently I only wrote two chapters because I lost interest. Although, I have plans to revamp the story, but it is still undecided as of now.
> 
> The original title of this is "Children of the Crescent Moon", but I changed it because I have an ongoing fanfic story with a kinda similar title.
> 
> This will be weird, so expect some weird and strange moments here. Okay, this will be a strange and creepy fanfic of mine, came from my imaginative brain...
> 
> This is supposed to going to be part of my abandoned AU series, "Angels of Death and Life Series" ...And as was expected, KoroGuri ship was here. 
> 
> I hope you enjoy this little gem.

The broken moon was shining brightly, like it did before it was shattered many years ago. Due to the gravity of the moon, it was eventually turned back into its round shape, although it was smaller than it used to be.  
  
Suddenly, like magic, the small round moon turned into a huge crescent moon again, like the one from 7 years ago, after the moon exploded due to a certain yellow creature.  
  
To people who noticed it, they will think that it was witchcraft, that is, if they believe in witches and magic. Some would say that it is because of lunar eclipse, supermoon, or something scientific.  
  
But in reality, it was more special than that. 

* * *

Outside the Class E building, the epicenter of the Class E incident which happened 7 years ago, there was a huge figure standing on the grassy area where the PE field used to be. The wind was blowing gently, as it ruffles the figure's dark robes.  
  
Anyone passing by would be scared at the strange sight, for the figure was clearly not human in a sense, and no human is 3 meters tall, but thankfully, no sane person will dare to climb the hill in the middle of the night, unless they are brave or utterly stupid.  
  
The huge shadowed figure looked at the broken round moon and grinned widely, as he whispered these two words,  
  
"It's time."  
  
His eyes turned to the cityscape below, the beautiful town of Kunugigaoka. It was now improved slightly, with a little change, but still the same town it was used to be. The main building of Kunugigaoka Academy was still standing on miles away from the hill he was standing, its tall and proud structure still looking as good as it was 7 years ago.  
  
The silver moonlight shone upon his dark figure, showing a little bit of the figure's identity. The figure is as yellow as corn, definitely not human. The huge necktie on his neck, slightly tattered and with a crescent moon emblazed on it, was flowing by the gentle breeze, along with his robes.  
  
Then the crescent moon emblem on the necktie began to glow, as the moonlight hit it. At the same time, something magical happened.  
  
The small round moon began to change shape, as it turned back into its crescent shape, like the one from seven years ago, after the 70% of the once great moon exploded.  
  
Then he begun to sing softly, but his voice echoes towards the entire forest, scaring the forest animals and some people residing near the hill.  
  
It was such a haunting melody.

* * *

**_"Come little children,_ **  
**_I'll take thee away,_ **  
**_Into a life of enchantment."_ **

* * *

He closed his small eyes as he continued to sing, as the birds of the night, the nightingales, was singing their wonderful melodies along with him.

* * *

_**"Come little children,** _  
_**The time's come to play,** _  
_**Here in my garden of shadows."** _

* * *

Then he opened his small eyes, but this time it was glowing brightly than any other.  
  
As he had begun the song, the time seems to have been stopped, and the scared people of Kunugigaoka begun to fell asleep, as if his voice had been lulling them to sleep.  
  
Except for some people.

* * *

On one house in the outskirts of the town, a couple was sleeping peacefully, before they heard that haunting song. They immediately woke up in alarm.  
  
"Have you heard that, anata?" a blond-haired woman asked his dark-haired husband, her blue eyes wandering around the room.  
  
Her husband nodded. "Yes, anata, I have heard it. In fact, that voice...it seems familiar..." he monotously said.  
  
The blond woman was worried, as she looked at the man. "What if it was him? What if he came back?" she mused, "You remembered that letter we had received 1 year ago?"  
  
The man paused, before answering, "That letter, which had warned us about the possible danger the kids will suffer?"  
  
The blond woman said, "Yes, and I am worried for the brats. He's...coming...and he would definitely taking them away."  
  
The man looked at his worried wife, before assuring her, "The kids will be fine. I am sure what the letter said is not true after all. Ghosts? Not real. And he is dead after all, we had made sure at that night. So you don't have to worry."  
  
The woman smiled. "Right. I shouldn't have worried. Those brats can handle it themselves, they are trained to be assassins after all. Well, before." She then stood up. "I should check up with Selene, to make sure if she's asleep."  
  
The man nodded, as he looked at his wife, who was going to their daughter's room.

* * *

"Oh boy, how wrong are they. They should have been heeded my warning. They should be...Class E...is in danger," a petite woman muttered, while she was looking towards the couple. She was outside of their house, peeking on them.  
  
At first, she looks human, with short black hair and black eyes, but the fluffy white wings on her back and a white aura gives her away, that she was not human.  
  
She shook her head, as she flew away from the humble home, her white wings flap harshly than before. It was clear that she was scared.  
  
"Their candles...the flames of those 27 people will be put out if they never did anything that will save their lives now...the angel of death...he will be going to take them away...to somewhere they can't return."  
  
"I can't fight him, even interfering with him. I know he only did this because he loved them, but this is not right. It is not their time. I can only warn them. I can't do anything...even for an angel of life like me."

**Notes for the Chapter:**

> See? This was a crappy story I made a year ago, the time when my mind started to go places when I became bored. This story was starting to get ridiculous, that is why I stopped writing the third chapter and lost interest. 
> 
> And for this story, can we pretend Koro-sensei can sing? *laughing out loud*
> 
> And for the record, I never changed the name of the Karasuma's little girl in this story! The name I gave her here was Selene, which means 'moon'. This story was made months before I created my very own version of the Karasuma's little daughter, which is now named Aimi, which is the second protagonist of my AC Next Generation fanfic story "The Slithery Child of the Crescent Moon". 
> 
> This was actually made on my old phone's messaging app because it was a crappy phone.


	20. The Crown of Trouble (Abandoned Story-In-Progress -  Magical Crown AU)

**Summary for the Chapter:**

> Koro-sensei and the Class E just wanted to enjoy the waters. Until they found something interesting.

**Notes for the Chapter:**

> This forgotten and abandoned AU story of mine, created last 2018 in script form, but now rewritten in 2019 in its short story form!
> 
> I made this because of that trendy Bowsette memes of the day. The crown made Bowser a female, so my mind always whispers, "what if Koro-sensei got it?" And this one was born. 
> 
> Unfortunately, I started to lose interest in the story. But I hoped I could continue this one, if I had the inspiration to do this.

  
It was a beautiful September morning on the little town of Kunugigaoka, and it was a perfect day for beach and outdoor activities. The birds are chirping, the gentle breeze are blowing, as the ever glorious sun is glowing brightly in the blue skies.   
  
That means it was a perfect day for adventure.   
  
On a little hill in the outskirts of the town, where a little building stood as the classroom of the Class E of Kunugigaoka Academy is, twenty-eight students and their strange alien-like teacher thought it was a perfect day to take a little trip around the lush Class E hill.   
  
Koro-sensei was walking through the mountain's forest with his young students, to enjoy its natural scenery, and to do some outdoor fun.   
  
Unfortunately for Koro-sensei, his teaching colleagues were unavailable at this moment. Karasuma-sensei was on a government meeting today, and Bitch-sensei was in the teacher's lounge, sleeping soundly in exhaustion due to her other assassination-related stuff.   
  
Koro-sensei just wanted his students to enjoy the beauty of nature and of course, to relax and have fun, so he had brought them around the hill. Besides Karasuma-sensei wouldn't mind for sure, as long as the secret of Koro-sensei's existence is still safe, and they will never went too far away from the building.   
  
As they navigate throughout the lush forest, Koro-sensei spotted a shining object from a nearby bush and cautiously approached it, as his 27 human and one AI students followed him. It was glistening, as its gold luster reflected the sun's rays, giving it a shine.   
  
Curiousity got the best of them, so they wanted to go near the object.   
  
But Koro-sensei senses a bad feeling about it. He raised his tentacle as he stopped, making his students follow suit.   
  
"Stop, boys and girls, and stay right there. I feel that this is not safe, so as a precaution, I will be the only one going to that gold thing." he spoke with concern and worry.   
  
Scared and confused, his students followed his warning and stood there behind him, as Koro-sensei approached it cautiously and slowly, his tentacles tensed in every move.   
  
Slowly, Koro-sensei picked up the shiny gold object, and suddenly, his round yellow face starting to go white with a emotionless expression.   
  
"A crown?" Koro-sensei's voice raised a pitch, as he inspected the crown intently, "Well, why would someone leave a precious and expensive-looking crown like this here, in the middle of a forest?"   
  
Yes, it was definitely a crown. Not just a fake plastic crown that young girls wear in costumes, but a real-looking one you can found on royalty.   
  
His students stared at the offending gold crown and sweatdropped, their expressions went to a deadpanned expression. They did not expect it to be a crown, of all things.   
  
Akabane Karma, a genius red-haired delinquent, also inspected the crown with intense eyes. "It looks real, alright. I could see the realness by just looking at it," he spoke with conviction.   
  
Kayano Kaede, a girl with green hair tied in bunny ear-looking pigtails, looks at the crown with narrowed eyes, "That was a pretty crown, and if it was a real crown just like Karma-kun said, it will be expensive. I am no expert in minerals, but I could guess it would cost millions or billions of yen, if you ask me."   
  
Shiota Nagisa, a feminine-looking blue haired boy, nodded as he agreed on Kaede. "With these shining jewels and crystals embedded in it, it will totally cost millions or billions of yen. It was really fit for royalty."   
  
Some Class E boys heard what Nagisa had said and their eyes went on a yen sign.   
  
"Well, I think we should auction it and made money from it!" Maehara excitedly exclaimed as he looked at the crown with fascination.   
  
Okajima nodded fastly as he shouted, his nose started to bleed, "Yeah, and with that hard cash, we can buy as many babes as we want!"   
  
Some boys agreed at what Okajima and Maehara had said, "Yeah!"   
  
But Koro-sensei never approved their plans for the crown. As their caring teacher, he never likes his students to steal something they weren't theirs, even though they did not know who the owner is.   
  
"Well, the best thing we should do is we should keep it safe and return it to its owner," Koro-sensei raised his tentacle and waved it, as his other tentacle held the crown.   
  
He called Ritsu, his AI student, from his smartphone. As soon as he looked at the phone, the phone's screen glowed, revealing a purple-haired girl.   
  
"Ritsu, may I ask if you can research about this crown?" Koro-sensei inquired.   
  
"Sure, Sensei! I would defintely help you! Just wait for a few moments, I will take long because I was not in my bulky body," Ritsu cheerfully replied.   
  
Koro-sensei thanked her and let it turn off, letting Ritsu to transfer at Nagisa's phone.   
  
He raised the crown to see it properly, and looks at it with wonder. His genius mind suddenly take places, and he imagined himself wearing the crown, and being a king of a certain kingdom, with his beloved Yukimura Aguri as his queen. They ruled the kingdom together in peace and harmony...or he imagined being a Demon King, feared by all.   
  
Unconciously, Koro-sensei suddenly removed his academic cap on his round head and wore the crown with anticipation. His students looked at him weirdly.   
  
Still dazed on his daydreaming, Koro-sensei grabs a face mirror from inside of his huge robes and preens, his eyes looked at the mirror in wonder. "Let me ask you all... Am I fit for a king?" He asks his students.   
  
His students sweatdropped, looking at their octopus teacher with a deadpanned expression on their faces.   
  
But they never knew that crown...That strange golden crown they found on the woods, will bring trouble to them than they expect.

**Notes for the Chapter:**

> DUN. DUN.
> 
> The crown of trouble, right?


	21. Nagisa's Poem for Koro-sensei (Poetry)

**Summary for the Chapter:**

> Nagisa's tragic poem for his dearest sensei who dearly cherished him and his classmates all over the year, while they were witnessing the death of the only teacher who had bothered to love them and nuture them.

**Notes for the Chapter:**

> A/N: Welcome to Oneshots and Tentacles Chapter 21! For a few chapters, I will be posting some poems I made ever since I got addicted to Assassination Classroom years ago. Majority of these focused on Koro-sensei's death, may it be in some student's POV.
> 
> I now posted poems in the series, since I still have to try writing tons of unfinished oneshots that was collecting dirt on the document manager. I could tell you, for months I was trying to create another KaraIri oneshot, but I still have to make sense of it.
> 
> So let's proceed for the poem, shall we? This poem was in Nagisa's POV.

The crescent moon was shining above,

As we are on your side,

Watching you smile and look at us with love,

As you waited for the twelfth hour to slide.

I cried, holding the knife,

That will end your only life,

Pointing to your heart, a weakness,

With my classmates holding you with sadness.

You told me to smile,

As you calmed my crying heart,

And made me say goodbye.

And I know it is not a lie.

I delivered the final blow,

As I pushed my knife to your heart,

And watched you glow,

And turn into little specks of yellow.

I cried to the crescent moon,

A broken howl, a sad lullaby,

As my tears will fall into the ground soon,

It is time to say goodbye.

_"Congratulations, my dear children,_

_Go and fly away like birds,_

_Cherish my memories and lessons."_

I could imagine you saying those words.

As we graduate in this assassination classroom,

We thank you, our dearest sensei.

For making us feel home,

With your love, care, and protection.

Thank you...and sayonara...

_**Koro-sensei...** _

**Notes for the Chapter:**

> This was originally posted in my FB years ago, but decided to post it here in order for you all to read. While writing this again for Fanfiction.Net and AO3, the Titanic's Theme started to play on my playlist and I started to cry.
> 
> I still never moved on Koro-sensei's death.   
> We all do.


	22. Karma's Elegy for Koro-sensei (Poetry)

**Summary for the Chapter:**

> Koro-sensei is the first teacher Karma had appreciated, so imagine how devasted Karma had been when Koro-sensei died. 
> 
> This poem captured all of that.

**Notes for the Chapter:**

> Same as Chapter 21, Chapter 22 is also a poem! But this time, it was on Karma's point of view, and longer than Nagisa's poem.
> 
> It was hard for me to write a poem and capture Karma's personality at the same time. I hope this will suffice.

The memories of your obnoxious smile are still here,

Haunting me from inside and out.

I promised myself not to cry,

But here I am...On your side.

Mourning for your loss,

Watching you fading away from us.

I felt like I had lost the person I really adored.

For you are the only teacher who really care for me.

You don't care if I was a demon,

Who always teases you and stole some loose changes.

You opened my eyes,

You changed me.

You gave me hope.

You let me shine.

You made me on top.

You made me realize my true potential.

I wanted you to stay, to be honest.

Even though I said I wanted to kill you.

I just wanted to remain our bond,

Assassin and target, that united us together.

Now on your final stand,

I just stood there hopeless.

Watching you defend us,

Your greatest weakness.

I saw you get tired,

I saw your smile.

I saw you face your own fate,

I saw you...fly away.

Little specks came to light,

As your tentacles in my hand starts to dissipate.

I looked at the crescent moon,

Trying to stop the tears that threatened to fall.

Why?

Why would you do it?

Why would you be gone?!

_**WHY?!** _

Then I realized...

It is the only choice.

You are happy,

That is all that matters.

I don't want you to fly away...

I don't want to break the bond,

But I had no choice.

Now it is time to let you go.

Sleep, my dear teacher,

And rest in peace.

The crescent moon is smiling,

And I know you are there.


	23. A Year To Forget

**Summary for the Chapter:**

> Koro-sensei received a hit on the head after a failed assassination attempt.
> 
> But why would he started to act differently to his precious students after being hit?

**_Nagisa's POV_ **

"Um... Koro-sensei, are you alright?" Kayano asked tentatively, as Karasuma and Irina were running towards us, concern and curiosity etched in their faces.

Our octopus sensei, Koro-sensei, was sitting in the ground, rubbing his round head, as he was seemingly in pain. We looked at each other as we wondered what happened to him.

Koro-sensei was usually alert, even though he was usually distracted. That is the real reason why no one, even us, can land a hit on him. But because of one little mistake in our newest assassination attempt, Koro-sensei, usual the caring and overprotective type of a teacher, had little time to save himself as he tried to save Hara and Fuwa from being hit by a falling projectile, namely a tree.

Yup, we had sacrificed a damn tree for an assassination attempt, and it backfired. I am sure that someone who planned all of this will get a load of scolding from Koro-sensei himself.

Speaking of Koro-sensei, it seems that his head was badly hit. And even though we are assassins supposed to assassinate Koro-sensei, considering he was currently down, we can't bear to even swipe a knife on him. Probably because of what he had revealed to us weeks ago.

Kayano Kaede, one of our classmates, was actually the sister of our former teacher Yukimura Aguri. Her real name is Yukimura Akari, she is an actress, and she has tentacles. She even claimed Koro-sensei killed Yukimura-sensei!

Because of that, it leads to a battle to death between Koro-sensei and Kayano, which we had found out from Itona-kun that the implanted tentacles could kill Kayano...and to end her bloodlust, I had kissed her on the lips.

I am sure I couldn't bear to look at Kayano in the eye for that.

Eventually, we found out Koro-sensei was once a human. Not only that, he was revealed to be the legendary assassin, the God of Death. Knowing he was actually a human, some of us hesitated to kill him, and instead wanting to save him, but some of us, like my bestfriend Karma, never agreed.

It leads to a 'civil war' of sorts, where our class were separated by two teams. We fought to let our voices be heard on the fate of Koro-sensei, and in hindsight, to settle the score between me and Karma.

Eventually we, the Save Team, won the battle. At the same time, my friendship with Karma has been restored like before and together, we find ways how to save Koro-sensei. The E-Class' bond became stronger than before, and we all give our thanks to our dearest Koro-sensei.

Until now, there was still no luck finding a way to save him, but we still never gave up, since March is has yet to come.

"Koro-sensei?" We all asked, as we gathered around at where Koro-sensei was sitting on the ground, dazed and confused. We all got worried for our teacher, since we had started to love him. He was an excellent and caring teacher, and it was the first time we had a teacher like that.

At a blink of an eye, Koro-sensei suddenly stood up and looked at us, his signature beady eyes narrowed, as his usual yellow turned a little grayish black, creating chills in our spines. Even Karasuma-sensei, who was the most emotionally-constipated than us, shivered at the stare and looked at Koro-sensei with apprehension. Irina-sensei looked scared, as she was holding Karasuma-sensei's arm protectively.

We all knew what that color means.

Pissed.

He must be angry at us.

Koro-sensei sighed, closing his beady eyes, as he started to speak. But what he had said next confused all of us. "Apprentice, come here! Where the heck is that kid?" he spoke in a cold voice, which was never heard in our dear happy-go-lucky teacher. Not even once. Although we already heard Koro-sensei's scary voice whenever he's pissed, his tone now was different from what we have been used to when he's angry.

Because we know that he still cared for us, even though he is angry. But now? I felt like he was a stranger.

A stranger that you were not supposed to meet.

We looked at each other as we try to figure out the words, as he spoke it in perfect English. Although we are not fluent in the foreign language, I could say I am amazed at how Koro-sensei was speaking it. And by the looks of my classmates and teachers, they were also feeling the same way.

Suddenly, Koro-sensei suddenly spoke in a language we don't recognize. We stared at him again in confusion, while Bitch-sensei was nodding to herself, even though her eyes were still as wide as saucers. It seems like Irina-sensei understood what Koro-sensei is saying.

But something made us more confused as ever.

_Apprentice?_

_Do he mean us?_

_His current stduents?_

_Or the Reaper, his former student?_

**_And what kind of language is that?!_ **

_"_ Um... Koro-sensei?" I tentatively asked, as my blue eyes looked at our teacher in apprehension. I also feel my classmates' fear, as I am good at analyzing emotions and wavelengths. Karma narrowed his eyes as he was gripping the Anti-Sensei knife tightly than ever, ready to defend himself and his friends even though he knew that he is no match for Koro-sensei. Even Karasuma and Irina-sensei was looking at Koro-sensei in apprehension, like they were ready to put their lives in front of the kids.

Koro-sensei groaned in annoyance and suddenly stared at us, his beady eyes still narrowing. His face was still grayish black, and we could see his teeth sharpening than ever. He was glaring at us like we were scums on the Earth, before turning to his usual yellow color, although we could still feel the malicious aura radiating around him.

We had all wished that we could now decode Koro-sensei's feelings right now, as he was still wearing that usual smile on his face. All year, we were trying to decode his emotions, and we got pretty good at recognizing it. But this time, the expression he was making was not familiar to all of us, as there was something mixed on it.

**_Malice._ **

Chill rises up in our spines when we all looked at Koro-sensei's beady orbs. Even I was trying not to fall down on my knees due to nervousness and fear. We still don't know why we felt that.

But we know that this is not our teacher we knew and loved.

We didn't expect what he say next.

_"Who the heck is Koro-sensei?"_

His voice lowered an octave as possible, as he was still glaring at us, as we stared at him with shock and confusion in our faces. Then he tried to walk towards us, as we stepped back. Emphasis on the word _tried._

He suddenly fell down, yelping in surprise as he was clumsily tangled in his multiple tentacled limbs. We sweatdropped at his actions, our fear suddenly forgotten. Some of us can't contain a chuckle, as some was brave enough to try helping Koro-sensei on his feet(?).

"Are you alright, Sensei? Don't worry, we are just trying to help you," Isogai, the ever polite class representative, asked Koro-sensei, who was looking at him with an apprehensive look, before holding Isogai and Terasaka's hands. He stood up clumsily, speaking again in that strange language.

We are not dumb to infer that Koro-sensei had spouting curses and inappropriate words. It was confirmed by Irina-sensei's raised eyebrow and a little snort. For her, it was not everyday you can hear a childish yellow octopus teacher curse like a sailor, although it was in a different language.

He then looked at his tentacles and touched his round face.

"What the heck with these... Slimy tentacles?! My body! My ever handsome face!"

He had glared at his tentacles like it was an assassination target waiting to be assassinated in his hands. The tentacles slithered and shivered, as if mocking the angry Koro-sensei.

Some of us rolled their eyes in annoyance, some snorted at his comment. We can never imagine what is Koro-sensei's appearance back when he was still a human, so his outburst can be true or just the ego talking.

"Give me a mirror, brats! Immediately!" He screamed at us who were suddenly looking in surprise, as Nakamura-san, ever the brave one, rolled her eyes and grabbed her pocket mirror in her skirt pocket.

Koro-sensei grabbed the mirror and saw at the reflection of his face in the mirror, then screamed like a girl. "MY FACE! WHY AM I LIKE AN EMOJI?!"

We can't contain our laughter at this one, even Irina-sensei falls to the ground, laughing uncontrollably. Karasuma-sensei raised his eyebrow, while some of us snorted.

Koro-sensei then stared at our laughing faces, growling like a rabid animal before glaring at us, throwing a tantrum. "WHY ARE YOU LAUGHING?! STOP IT!"

When he realized that we can't stop laughing, he folded his tentacles in his chest, pouting angrily, before sighing and stared at us with a glare. "Who the heck are you, and why am I, the God of Death, the world's greatest assassin, here in this place?" Koro-sensei then spoke loudly in confusion, as he was still looking at his tentacles in disgust, then at us.

We stopped laughing (even Okano-san kicking the laughing Maehara in the gut), and stared at our octopus teacher in confusion and shock at the octopus in front of us, who was still glaring at us like he wants to kill us on the spot, then at the tree which hit Koro-sensei's head, and to each other.

Even the most simple minded could actually figure out what happened to our sensei. And one conclusion popped up in our minds, as we stared to each others' eyes, we all thought the same words.

**_Great. Koro-sensei has amnesia._ **

**Notes for the Chapter:**

> Welcome to Chapter 23 of Oneshots and Tentacles!
> 
> This idea of mine was actually made months ago, but decided to rewrite it and placed it here.
> 
> In this one, Koro-sensei has forgotten everything that happened after he was captured by Shiro, due to a failed assassination attempt, and that means all memories of the E-Class and Aguri Yukimura were erased in his mind.
> 
> This one was placed between the Civil War arc and the Valentine episode. And sorry that Koro-sensei is actually an OOC here.
> 
> I don't know if when I am going to update my other stories, since I have schoolwork to do, and I am currently down with damn measles.
> 
> See you on the next updates, guys!


End file.
